UMAD_OPEN_PORT(3)

✨ UMAD_OPEN_PORT ✨

okay bestie, gather round, because today we're opening an InfiniBand device port for umad access and it's genuinely not that deep 💅 this little function lives in the OpenIB Programmer's Manual and it's the glow-up your HPC code has been waiting for.

🌸 NAME 🌸

umad_open_port — open an InfiniBand device port so you can do umad things with it 🦋

🎀 SYNOPSIS 🎀

#include <infiniband/umad.h>

int umad_open_port(char *ca_name, int portnum);

💖 DESCRIPTION 💖

So here's the vibe: umad_open_port() opens port portnum of the IB device ca_name for umad access. That's it. That's the whole job. She's a simple girl with a simple dream 🙈

And like, if you don't hand over all the parameters? No stress. The library will pick the port for you — it's giving very "I got you, bestie" energy. (The deets on how that selection actually works live over in umad_get_port(), so go peek there if you're nosy. 👀)

⭐ RETURN VALUE ⭐

On success you get 0 or a unique positive value — that's your umad device descriptor, your little ticket to ride 🎟️✨

On error you get a negative value, and which negative value is honestly a whole mood board:

• -EOPNOTSUPP — the ABI version doesn't match 😭 they're not on the same wavelength, it's giving incompatible
• -ENODEV — the IB device can't be resolved 💀 can't find her anywhere
• -EINVAL — the port is not valid (bad portnum or no umad device) 🚫 nope, not it
• -EIO — the umad device for this port can't be opened 😔 so close and yet so far

lowkey check your return values, bestie. negative means something went wrong and the kernel is NOT being subtle about it.

🦋 SEE ALSO 🦋

• umad_close_port(3) — because everything you open, you eventually gotta close 🫶
• umad_get_cas_names(3) — for finding out what CAs even exist around here
• umad_get_port(3) — the one with the details about port selection 👑

👑 AUTHOR 👑

Hal Rosenstock <halr@voltaire.com> — an actual icon, we stan 🌈

and that's the whole page, periodt 💜 this beauty shipped as part of OpenIB back on May 21, 2007, and the manual name is UMAD_OPEN_PORT in section 3 — so if you ever forget, just man 3 umad_open_port and she'll be right there waiting for you. mwah 💋